Okay, I can absolutely see why you are upset. I think you guys need to sit down and look at your relationship rules again. Are you all meant to be equals, or are you seen as a secondary to the both of them? Do they love you, or do you only have a sexual relationship?
Sleeping together (regardless of sex) is an intimate act. If you have an intimate relationship, it's really only fair that you get that side of it too.
Is the wife trying to keep you in a box (in her mind), not fully sharing her husband with you? What's her deal here?
Incidentally, I had the same issue with my gf's hubby at first. Whenever she slept in my bed, he'd roam about the house all night, completely stressed out, not able to sleep, causing a bit of a fuss. After about three months, he slept like a baby and no longer seems to mind.
That being said, because he seems so needy, and I am stronger, I don't mind him 'having' her more than I 'get' her. I'm happy with a bit less. I just like a schedule.
Basically, if you're meant to be their other primary, if you have an intimate and not just a sexual relationship, then you have the right to have all the elements of that. If she's willing to be poly, she has to be willing to compromise. It might do her some good. It's not healthy to depend on another person so much that you can't bear even two nights a week!
Not an easy position for your bf to be in, either.
She's not going to die, to be blunt. She needs to suck it up a little and start playing fair.
----
Now that I've said this, also consider if is there anything you might get more than she does. Is it possible that she feels you two have better sex than she does with him, for example? She may not be being vindictive, perhaps she just feels like she's getting the short end of some other stick. Just a suggestion. I could be wrong.